On Christmas Day 1978, almost exactly a year after the implosion of the Sex Pistols while on tour in San Francisco, the artist formerly known as Johnny Rotten unveiled his new band, Public Image Ltd, at the Rainbow theatre in London. The audience, John Lydon remembers with amusement, were "nauseated, because the bass frequency was so low your bowels started to vibrate". He lets out his familiar arch cackle. "Well, it's a different experience at Christmas."

Lydon has now chosen to relaunch PiL, after a 17-year hiatus, with a series of pre-Christmas shows. In the interim, he has reformed the Sex Pistols twice, but PiL, he maintains, are his "first love". Over the course of eight albums and as many lineups, PiL were as inspired and confounding as their frontman. Their ferociously inventive early work has influenced bands such as Massive Attack, the Manic Street Preachers, Primal Scream and any number of this decade's post-punk revivalists. Their return should be interesting. "It feels clean," says Lydon. "It's refreshing."

Indeed, a clean start was the original point of PiL. Lydon was sickened by punk even at the height of the Sex Pistols' fame. "I don't like cliches, I don't like entrapments, I don't like uniforms, and punk was getting into a real problem with that. It's very sad seeing people filling up the first 10 rows trying to look exactly like you." After the band disintegrated, Lydon, broke and forbidden by former Pistols manager Malcolm McLaren even to use the name Rotten, spent some time in Jamaica, seeing how dub-reggae producers worked.

"It was the spaciousness," he says. "For me, the best rock is not what you play – it's what you're not playing." Back in England, he recruited a new band (childhood friend Jah Wobble on bass plus former Clash guitarist Keith Levene), named them after a Muriel Spark novel, and buried the myth of the Sex Pistols with their first single, simply called Public Image: "You never listened to a word that I said/ You only seen me from the clothes that I wear."

The PiL lineup that recorded the benchmark post-punk albums First Issue and Metal Box will not, however, be returning. "They're off on their own tangents," Lydon says vaguely. Are they all still friends? "Wobble always, yes. Keith used to be, but he went off into his own little universe and never came back." After they departed (Wobble in 1980, Levene in 1983), PiL went through several incarnations: on 1986's Album, Lydon worked with a bizarre selection of musicians, including guitar hero Steve Vai, Cream drummer Ginger Baker and even (although his contributions went unused) Miles Davis.

The current PiL features two late-1980s members: guitarist Lu Edmonds and drummer Bruce Smith, plus one new arrival, multi-instrumentalist Scott Firth. "We'll see where we can go," Lydon says. "Some things may be quite similar. Some may not."

Part of the impetus for PiL's return seems to have been emotional. Last year, Lydon lost his father and learned that his brother had cancer (now in remission) – events that reminded him of the early days of PiL, when his mother and his friend and former bandmate Sid Vicious died. His mother's passing inspired Death Disco, a howling punk-funk exorcism that surely remains one of the most harrowing songs ever to grace Top of the Pops. With Wobble's enveloping basslines, Levene's unsettling guitar and Lydon's knife-on-glass vocals ("like a bag of cats being slung down a staircase" is his own description), PiL were sonically radical but never cerebral. "It's not about being in or out of tune," he says. "The Sex Pistols were too rigid. PiL allowed me to express proper emotions. So I really wanted to get out and do [Death Disco] properly live again."

Lydon refuses to define PiL's sound or agenda. "When I finally cease working, then you can make a judgment on what PiL is or isn't," he says tartly. "For me, it's an unfinished work which is set to continue for some time." Though a fiercely bright autodidact – a product of what he calls Britain's "self-education system" – Lydon dislikes anyone he sees as overtly intellectual or pretentious, which includes such esteemed writers about his work as Jon Savage and Greil Marcus. Analysis, I am slow to realise, irritates him intensely. I make the mistake of asking him if he evolved the band by following his musical whims.

"Whims?" he spits, sounding uncannily like Sir Alan Sugar in high dudgeon. "Whims! That's the most ridiculous word to use. There's no whim to any of it. All right? It's all about the emotions. I attack my weaknesses head-bang-fucking-on, and it's quite painful for me at times – and it's important."

Well, I press on unwisely, the later records, including hits such as Rise and Don't Ask Me, were far more pop-friendly than the early ones. "I disagree entirely," he says, with something like disgust. "I think that trying to label and categorise is actually to the destruction of a band like Public Image. You must not make such fake accusations. Otherwise you are missing the point. Big time." So any attempt to analyse PiL's history is missing the point? "Well, if you have the nerve and gall to tell me that you know me better than myself, ab-so-lute-ly!"

Oh dear. But if Lydon is quick to take offence, then he is, thankfully, just as quick to forget it. His annoyance abruptly subsides as he explains that he is jittery about the wildfires ravaging California; he can see the smoke from his window. He has lived in Los Angeles with Nora Forster, his wife of 30 years, since the early 1980s, but still maintains UK citizenship. Does he enjoy returning to Britain? "It's always strange. It's brilliant the vibe you get off the cab driver – as soon as he opens his mouth you feel great – and then you see the horrid little streets and it all feels like a big toytown. And then you become reacquainted with it and stop being so, well, spiteful to your past."

On a recent visit, he says, he berated some schoolkids for throwing stones at passing buses. "Younger people at the moment are very mouthy and aggressive," he complains, oblivious to the irony. "You're all terrified of your own youth. You're not allowed to give them a clip around the ear and send them home." But weren't people scared of him in his youth? "Mmm. That was the power of words, but this lot use violence."

Lydon was never the folk demon he was seen to be during the Sex Pistols' firework-like lifespan, but it has still been strange to watch him become a cantankerous national treasure. Since his improbable appearance on I'm a Celebrity . . . Get Me Out of Here! in 2004, he has hosted well-regarded nature documentaries and become the face of Country Life butter. Despite his thirst for innovation (he was an early adopter of hip-hop and techno), he sounds rather old-fashioned at 53, brushing aside current bands ("a bit too manufactured"), digital music ("far too cold and detached") and computers in general: "My eyesight's gone. They drive me insane. How many mpegs of saucy goings-on do you have to squint at before you learn this is no good?" The only person, aside from his band and family, whom he expresses any enthusiasm for is David Attenborough, who is "fantastic!"

Yet trouble continues to follow him around. Over the last couple of years, he or members of his entourage have been accused of assaulting Roxane Davis (an assistant on a US TV show he was appearing on) and Bloc Party frontman Kele Okereke; and of having a run-in with Duffy at an awards ceremony. "People are told that's what there'll be and therefore they believe it," he says. "I've turned arrogance into an artform, where it's so absurd that it becomes comedy. But I've never done anything to hurt anybody or steal from anyone."

It's strange how his tone swings so often between imperious disdain and wounded sincerity. A little later he adds: "I would like to be a good person." Does he think he is? "Well, I'm going to work at it. You can always wake up on the wrong side of the bed and boo-hiss everyone suffers. We can all be temperamental."

Is being on his bad side a frightening experience? "It would be very hard to get there. You'd really have to work at it. I can't carry on hatreds because they become almost amusing. I don't actually hate Malcolm [McLaren]; it's just fun to hate him. He's just one of those people." His voice softens into amused melancholy. "I think what we're getting to here is so am I."

We're out of time. Lydon has to go. "Let's hope the Guardian's as poisonous as ever!" he says cheerfully. I quickly remind him of a line from 1979's Chant, about urban violence: "It's not important/ It's not worth a mention in the Guardian."

The cackle rattles out again, this time with real relish. "Isn't life fun?" he says.